Photoelectric detector is a critical device in optical communication systems. Silicon-based photon technologies have witnessed their fast development in recent years. Silicon-germanium photoelectric detector that is compatible with CMOS (Complementary Metal Oxide Semiconductor) processes will be widely applied owing to their capability to be monolithically integrated with other silicon-based photonic devices. However, in addition to being absorbed by germanium to generate an electrical signal, another part of an optical field is absorbed by heavily germanium-doped region and through-holes, thereby incurring additional losses and degrading the responsiveness of silicon-germanium photoelectric detector.